The Tor Browser: mfbt/decimal/floor-ceiling.patch@7e26c7da4463

     1 diff --git a/mfbt/decimal/Decimal.cpp b/mfbt/decimal/Decimal.cpp

     2 --- a/mfbt/decimal/Decimal.cpp

     3 +++ b/mfbt/decimal/Decimal.cpp

     4 @@ -618,26 +618,26 @@ Decimal::AlignedOperands Decimal::alignO

     5  Decimal Decimal::ceiling() const

     6  {

     7      if (isSpecial())

     8          return *this;

    10      if (exponent() >= 0)

    11          return *this;

    13 -    uint64_t result = m_data.coefficient();

    14 -    const int numberOfDigits = countDigits(result);

    15 +    uint64_t coefficient = m_data.coefficient();

    16 +    const int numberOfDigits = countDigits(coefficient);

    17      const int numberOfDropDigits = -exponent();

    18      if (numberOfDigits < numberOfDropDigits)

    19          return isPositive() ? Decimal(1) : zero(Positive);

    21 -    result = scaleDown(result, numberOfDropDigits - 1);

    22 -    if (sign() == Positive && result % 10 > 0)

    23 -        result += 10;

    24 -    result /= 10;

    25 +    uint64_t result = scaleDown(coefficient, numberOfDropDigits);

    26 +    uint64_t droppedDigits = coefficient - scaleUp(result, numberOfDropDigits);

    27 +    if (droppedDigits && isPositive())

    28 +        result += 1;

    29      return Decimal(sign(), 0, result);

    30  }

    32  Decimal Decimal::compareTo(const Decimal& rhs) const

    33  {

    34      const Decimal result(*this - rhs);

    35      switch (result.m_data.formatClass()) {

    36      case EncodedData::ClassInfinity:

    37 @@ -660,26 +660,27 @@ Decimal Decimal::compareTo(const Decimal

    38  Decimal Decimal::floor() const

    39  {

    40      if (isSpecial())

    41          return *this;

    43      if (exponent() >= 0)

    44          return *this;

    46 -    uint64_t result = m_data.coefficient();

    47 -    const int numberOfDigits = countDigits(result);

    48 +    uint64_t coefficient = m_data.coefficient();

    49 +    const int numberOfDigits = countDigits(coefficient);

    50      const int numberOfDropDigits = -exponent();

    51      if (numberOfDigits < numberOfDropDigits)

    52          return isPositive() ? zero(Positive) : Decimal(-1);

    54 -    result = scaleDown(result, numberOfDropDigits - 1);

    55 -    if (isNegative() && result % 10 > 0)

    56 -        result += 10;

    57 -    result /= 10;

    58 +    uint64_t result = scaleDown(coefficient, numberOfDropDigits);

    59 +    uint64_t droppedDigits = coefficient - scaleUp(result, numberOfDropDigits);

    60 +    if (droppedDigits && isNegative()) {

    61 +        result += 1;

    62 +    }

    63      return Decimal(sign(), 0, result);

    64  }

    66  Decimal Decimal::fromDouble(double doubleValue)

    67  {

    68      if (std::isfinite(doubleValue))

    69          return fromString(String::numberToStringECMAScript(doubleValue));

    71 @@ -915,16 +916,18 @@ Decimal Decimal::round() const

    72          return *this;

    74      uint64_t result = m_data.coefficient();

    75      const int numberOfDigits = countDigits(result);

    76      const int numberOfDropDigits = -exponent();

    77      if (numberOfDigits < numberOfDropDigits)

    78          return zero(Positive);

    80 +    // We're implementing round-half-away-from-zero, so we only need the one

    81 +    // (the most significant) fractional digit:

    82      result = scaleDown(result, numberOfDropDigits - 1);

    83      if (result % 10 >= 5)

    84          result += 10;

    85      result /= 10;

    86      return Decimal(sign(), 0, result);

    87  }

    89  double Decimal::toDouble() const

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